Skip Navigation


Journal of Petrology Advance Access originally published online on September 24, 2004
Journal of Petrology 2005 46(1):109-133; doi:10.1093/petrology/egh064
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Supplementary data
Right arrow All Versions of this Article:
46/1/109    most recent
egh064v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by HARPP, K. S.
Right arrow Articles by WERNER, R.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Petrology vol. 46 issue 1 © Oxford University Press 2004; all rights reserved

The Cocos and Carnegie Aseismic Ridges: a Trace Element Record of Long-term Plume–Spreading Center Interaction

KAREN S. HARPP1,*, VIRGINIA D. WANLESS1,{dagger}, ROBERT H. OTTO1,{ddagger}, KAJ HOERNLE2 and REINHARD WERNER3

1 DEPARTMENT OF GEOLOGY, COLGATE UNIVERSITY, 13 OAK DRIVE, HAMILTON, NY 13346, USA
2 DYNAMICS OF THE OCEAN CRUST, IfM-GEOMAR, WISCHHOFSTR. 1–3, 24148 KIEL, GERMANY
3 TETHYS GEOCONSULTING GmbH, WISCHHOFSTR. 1–3, 24148 KIEL, GERMANY

The aseismic Cocos and Carnegie Ridges, two prominent bathymetric features in the eastern Pacific, record ~20 Myr of interaction between the Galápagos hotspot and the adjacent Galápagos Spreading Center. Trace element data determined by inductively coupled plasma-mass spectrometry in >90 dredged seamount lavas are used to estimate melt generation conditions and mantle source compositions along the ridges. Lavas from seamount provinces on the Cocos Ridge are alkalic and more enriched in incompatible trace elements than any in the Galápagos archipelago today. The seamount lavas are effectively modeled as small degree melts of a Galápagos plume source. Their eruption immediately follows the failure of a rift zone at each seamount province's location. Thus the anomalously young alkalic lavas of the Cocos Ridge, including Cocos Island, are probably caused by post-abandonment volcanism following either a ridge jump or rift failure, and not the direct activity of the Galápagos plume. The seamounts have plume-like signatures because they tap underlying mantle previously infused with Galápagos plume material. Whereas plume heterogeneities appear to be long-lived, tectonic rearrangements of the ridge plate boundary may be the dominant factor in controlling regional eruptive behavior and compositional variations.

KEY WORDS: mantle plume; mid-ocean ridge; Galápagos; abandoned rift; partial melting of the mantle

* Corresponding author. Telephone: (315)228-7211. Fax: (315)228-7187. E-mail: kharpp{at}mail.colgate.edu


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Geological Society of America Special PapersHome page
J. G. Fitton
The OIB paradox
Geological Society of America Special Papers, January 1, 2007; 430(0): 387 - 412.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.